https://github.com/mattermost/mattermost-webapp/pull/1679 led to changes to master being merged to v5.3 on T-3.
This was caused by a change of the base branch prior to merge, which led to all the changes being merged to v5.3.
As a result, at least 100 strings with HTML elements such as links do not render correctly for non-English languages. Moreover, some strings are no longer translated. These affect various places in the UI including the tutorial, search, Account Settings and the System Console. Few screenshots posted below.
Moreover, it is unclear what other undesired effects merging the master branch to v5.3 at T-3 had.
The following steps are taken to fix the issue:
1. Revert all commits in https://github.com/mattermost/mattermost-webapp/pull/1679
2. Confirm Redux version is correct after revert, and update if necessary
3. Re-submit translations PR https://github.com/mattermost/mattermost-webapp/pull/1685
4. Re-submit date picker UI fix https://github.com/mattermost/mattermost-webapp/pull/1679/commits/8bd9d67af9c6deef37e6432c48a3e954c1ea9168